Differential gear control device



Sept. 9, 1952 l.. H. PlxLER ErAL DIFFERENTIAL GEAR CONTROL DEVICE Filed June 2, 195o .Re mmm.. y Tux E MPH n Vd. m www, W Rw A ZM V. B www Patented Sept. 9, 1952 Louis H. Pixler,

Englewood, and Harry B. Pixler, Denver, Colo. I

Application June 2, 1950, Serial No. 165,7 02

automotive differential gearing. Automotive differential gearing is designed to allow one rear wheel to travel at a different'rate of speed than the other rear' wheel when the vehicle is traveling in an arc. This, of course, is a necessary function. However, the conventional differential gears allow one wheel to spin in mud, snow, or other slippery traction without imparting any driving torque to the remaining wheel.I rThis makes it exceedingly `difficult to extricate the vehicle from mud' holes and theIlike, and also causes slippage or an uneven traction onslippery roads, thus creating sideskidding and making it difficult to control the vehicle.

The principal object of this invention is to provide a device which `may be applied to the conventional automotive differential gearing which will act to prevent either wheelfrom suddenly rotatingfaster than the other wheel under poor vention, reference is had to the accompanying drawing which forms a parthereof. Like-numerals refer to like parts in all views of the drawing and throughout the description.

In the drawing: -II Fig. 1 is a longitudinal section through a conventional automotive -I vehicle I differential looking rearwardly, illustrating a side View of the axle mechanism with the invention in place thereon;

Fig. 2 is a similar section ofY one half of Fig. 1, taken on the line 2--2, Fig. 3, with the axle mechanism shown in section; and r Figs. 3, 4, andare `cross-sections taken on the lines 3 3, 4-4, and 5--5, respectively, Fig.`1.

5 claims. (o1. 74-711 the inner extremities of the axles I9 and 20 and rotatably fitting a spring sleeve 2| over the inner extremity of each. `The spring sleeves bring the diameters of the reduced portions of the axles to the same diameter as the adjacent axle surfaces. The spring sleeves 2| are secured to the hubs `I5 in any desired manner. As illustrated, they are provided with tenons 32 which enter receiving notches formed in the hubs I5.

A flat bar or wire of resilient metal, preferably spring steel, is helically and tightly coiled about each collar 2| to form` what might'be termed cylindrical helical springs 22. The springs at the two` sides of the differential gears are wound in opposite directions, as shown in Fig. l. The springs 22 extend along the large diameter portions of the axles I9 and 2li for a distance substantially equal to the length of the collars 2 I. The portions of the springs 22 about the enlarged portions of the axles are surrounded by control sleeves 23. The outer extremities of I the bars or wires forming the springs 22 are passed through openings 24 in the sleeves 23 and areqturned back upon themselves, as shown in Fig. 5, to form locking hooks 25 which lock the oiaiter extremities of the springs 22 to the sleeves 2 The sleeves 23 are rotatably supported in roller bearings 26 by means of which they are mounted in outer bearing cups 21. The outer extremities of the sleevesI23I bear against retaining rings 28 which in turn bearagainst friction washers 29 f riding against closed outer ends 3D in the cups 21.

In the drawing. theright-hand portion of a I rear axle housingi's'indicated at III, and the lefthand portion thereof is indicated at I i. The two portions are joined at a differential housing I2. The differentialhousing I2 contains the usual bevel gear I3 mounted on and` arranged to rotate a differential gear case I4. Tzhegearcase I4 is supported at its sides onhubs I5 rotating in suitable anti-friction bearings I6 in the axle housings |0 and The gear .case I4 supportsthe usual planet gears, indicatedat I1, about' axle drive gears I8 into which the extremities of two rear axles I9 and 20 are splined. I

As thus far described, the mechanism is conventional in most automotive vehicles. The invention is applied by reducing the diameter 0f The turns of the springs 22 are normally slightly separated. When installed, however, the cups 21 are forced toward the gear hubs I5 'sufciently to bring the turns of the spring substantially together, and the cups 21 are locked in this compressing position by means of set screws 3| threaded through the rear axle housings I0 and I I so that the springs actto resiliently hold the rings 28 and the cup ends 30 in frictional engagement. I

Let us assume that the vehicle is being driven straight forward. The two axles I9 and 20 :are rotating forwardly, as Shown by the arrow A in Fig. 1. The bevel gear I3, the gear case I 4, the hubs I5, the springs 22, and the sleeves 23 are all `rotating at the same speed as the axles I9 and 29. Now let us assume that the left wheel reaches slippery traction which allows the left axle I 9, in Fig. 1, to suddenly rotate faster than the right axle 2t due tothe fact that the planet gears will travel `about the axis of the right drive gear I3A as is usual with differential' transmissions. This willcause the gear case I4 and its hubs I5 to rotate forwardly faster than the axle 2|) is rotating forwardly. The result is to cause the inner extremity of the right spring 22 to be rotated forwardly faster than the outer extremity thereof, since the outer extremity is retarded by thefriction of the rollers 26 and the friction between the members 28, 29, and 30. This places a winding. torque on the right spring 2'2, causing it to tightly wind about and grip the axle 20 and the left collar 2i. This tends to cause the gear case to rotate in unison with the right drive gear opposite axle i9 to lock the gear case I-'lto the latter. The gripping action of the springs is instantly released as soon, as'. the planet caseY and axle resume the samespeedl due tothe natural resiliency oi theA springs, which will return them to their normal Vnon-gripping diameter;

- Slow relative changes between thespeeds of the axles. and the speeds ofthe gear casing! are confipensatedv byrelative movement' between the control sleeve 23- and the bearing cup. 2l' so 'that the springs arenotwound and contracted. Reversel rotation of theaxlesl simply tends to unwind or diametrcally expand the springsA so that there is no clutching actionin reverse.

It is well known that when a` helieal spring of the ty-pe employed-in this invention is wound to decrease its diameter, thereis a natural tendency for the turns. or" the spring to crowd together so as to shorten the over-'all length of.v the'sprin'g coil. springs 22 to. shorten. when vthey' approach the axleegrippilng position', so that the'springV pressure on the friction washer 2id is released in proportion tothe gripping action'.

While a specic form ofthe.'improvement-has been. described and; illustrated? herein, itv is' tobe understood that the same may'beivariedl, within the scope of' the' appended.' claims, 'without d`eparting from the spirit of the invention.

`Having thus described. the invention, what is claim-ed andi desired secured b'y Letters Patent'is:

lf. In any automotive'diiereirtial gear of the type havinga planet gear case` joining two Saxles, means for preventing: either 'axle from ksiid'denly rotating faster than the other, comprising: acollar secured toV and extending outwardly from each side of said case aboutoneoi4 said axles,v said axle having a reduced diameter portionwhich is roe tatable in said collar, the portion of said axle r adjacent said collar being offuni'form external diameter therewith and' av helical spring wrapped about said collai` and aboutthe adjacent axle so that' whenk said collar tends to rotatev forwardly faster than said axle, said spring will wind so as to contract about both the collar and the axle so as to tend to lock the same together.

2` 1n an auto-motive differential gear of the type having a planet gear case joining two axles, means for preventing either axle from suddenly rotating faster than the other, comprising: a helical spring secured to each side of said gear case, each spring extending outwardly about one of said axles, said springs being wound so that they will be contracted about their respective axles whenever the speed of the gear case exceeds the speed of that axle; a sleeve surrounding'and secured to the outer extremity of each spring; a

bearing cup surrounding and providinga bearing This natural phenomenon causes. the

helical spring secured to each side of said gear .'case; each spring.A extending;` outwardly from said 'gear case about one of; said axles, said sprmgs being woundvso that they will be contracted about their respective axles whenever the speed of the gear casefexceeds the speed of that axle; a sleeve surrounding and secured to the outer extremity of each spring; abearing cup surrounding and providing a bearing to allow rotation of said sleeve in. saidr cup; means for preventing rotation of said cup; and friction-creating means between said sleeve and said cup resisting relative rota- Y tion between said sleeve and said cup.

4". InV an automotivedifferential gear of the type having a planet gear case joining two axles, means for preventing either axle. from suddenly rotating faster'thant the' other, comprising: a helical spring?secured-toeach side of said gear case, each springfextending outwardly from said gearl case about one ofsaid axles, said springs beingwound sov that they will be contracted about theirV respective: axles; whenever the speed of the gearv case exceds--the speed. of that axle; a sleeve surrounding and'secured to the outer extremity ofy each spring; abeari-ng cup surroundingY andI providing a bearing to allow rotation oi said sleeve in said cup; means-for preventing .rotation of said cup; and friction-creating means between. the extremity of said sleeve and said cup 'resisting relative rotation betweenV said sleeve and said cup when said `spring is expanded, said frictioncreating means being arranged to move longitudinally with said spring so'that the friction will be released when said spring iscontracted.

5. In an automotive differential gear of the typehaving a; planet gear case joining two axles, means for preventing eitherA axle `from suddenly rotatingfaster than the other., comprising: a collar secured to and extending outwardly from each side of said case about one of said axles, said axle having a reducedidiameter portion which is rotatable in said. col-lar,k the portion of said axle adjacent said collar being ofV uniform external diameter therewith; a helical spring Wrapped about saidV collar and about the adjacent axle so that when` said collar tends to rotate forwardly faster than rsaid axle, said-spring Will wind so asA to contract about bothjthe collar and the axle so as to tend to lock the same together; a sleevel surrounding and secured to the outer extremity of eachv spring ;l a bearing cup surrounding and pro- Vidi-nga bearing for said collar; means for preventingv rotation of said cup; and friction-creating means betweenv the extremity of said sleeveY and saidA cup to. resist rotation of said sleeve vwhen said spring is expanded, said friction-creating means being arranged to moveV longitudinally with said spring.l so that the friction will be releasedwhen saidspring is contracted.

' .LOUIS H. PIXLER.

.'HARRYB. PIXLER. I

. v.REFERENCES CITED The following references are of record inthe le of this patent:

STATES. PATEN'I'S` 

